Some electronic equipment manufacturers design different circuit board modules with common dimensions (e.g., the same heights, the same lengths, etc.). For example, suppose that a manufacturer wishes to offer a mid-range processing module having a first type of connector, and a high-end processing module having a second type of connector. The manufacturer may see advantages to using a similar circuit board layout for each module and thus want to keep the height and length of the two processing modules the same. Additionally, the manufacturer may see advantages using a single layout for an interconnect (e.g., a midplane, a backplane, etc.) to which either the mid-range processing module having the first type of connector, or the high-end processing module having the second type of connector, will connect.
If the mid-range processing module and the high-end processing module have the same general shape and appearance, it may be difficult for someone to distinguish the two modules from each other. Accordingly, the likelihood exists that the person (e.g., a technician) may inadvertently attempt to connect the mid-range processing module having the first type of connector to the high-end interconnect, or alternatively attempt to connect the high-end processing module having the second type of connector to the mid-range interconnect. A source of further complication is the fact that such a processing module typically engages an interconnect in a blind-mating manner thus preventing the person from simply making a visual comparison of the connector layout of the processing module with the connector layout of the interconnect.
To prevent that person from inadvertently connecting the wrong processing module to the wrong interconnect, the manufacturer may rely on that person to exercise extreme care when handling processing modules. For example, one approach to preventing connection of the wrong processing module to the wrong interconnect (hereinafter referred to as the labeling approach) involves placement of conspicuous matching labels on the mid-range processing module and the mid-range interconnect, and placement of different matching labels on the high-end processing module and the high-end interconnect. Accordingly, the person will be able to avoid inadvertent connection of a mid-range module to a high-end interconnect, or vice versa, by performing a close comparison of the labels.
Another approach to preventing connection of the wrong processing module to the wrong interconnect (hereinafter referred to as the sensing approach) involves training the person to physically sense when a processing module properly aligns with a correctly matching interconnect, and when the processing module improperly aligns the wrong interconnect. In particular, as the person moves the connectors of the processing module into contact with corresponding connectors of the interconnect, the person will be able to manually feel whether the processing module matches the interconnect. Specifically, if the person attempts to provide an extraordinary amount of force and the processing module fails to connect with the interconnect, the person knows that the person is attempting to connect the wrong processing module with the wrong interconnect and that the person should stop the attempt.